Several types of guards are used to prevent a patient falling out of bed. The patient is prevented from falling off the patient support of the bed either by several side rails cooperating together or by a single side rail protecting the majority of the side of the patient support. These side rails are permanently fixed to the bed in such a way that they are able to collapse down and thus the patient is able to leave the bed or the medical personnel is afforded better access to the patient and simpler handling with the patient.
Several mechanisms are used for locking the guard. Most of these mechanisms are permanently attached to the side rail, which is permanently attached to the bed in such a way that it can move between the collapsed and raised position. These positions are achieved by a combination of horizontal and vertical movements. Another disadvantage of currently used mechanisms is the insufficient protection against movement of the guard. Most used solutions contain only one safety element, which in some cases could be overcome by an unintentional movement.
The locking of the guard via a lever mechanism is described in CN201905562U, where the unlocking of the guard is realized by a movement of the lever mechanism which lifts the entire body of the guard in relation to the side rail. The guard can then be rotated around an axis located in the side rail. This solution overcomes the problem of spontaneous unlocking of the guard because unlocking of the guard is achieved by a vertical movement of the lever.
The guard described in JP2004357875A is equipped with another locking system, but in this case spontaneous unlocking of the guard is not entirely avoided because it is performed on a horizontal plane. This feature works as rotational extension of the side rail. The locking mechanism is constructed in such a way that the raised part at the top end of the guard engages the opening in the vertical support of the side rail. The lock is unlocked by the pin being released and moved through the cut of the collar located in the lower part of the guard. However, any of the described solution doesn't provide complete protection of spontaneous unlocking of the guard and its subsequent movement.
Document JP2003052764A describes a guard system with a limited movement. It consists of a rotational mechanism. The coupling is realized by a screw. The rotation is limited by a rectangle which is a part of the side rail and which is stopped by a protrusion which is part of the guard. This guard can be moved around a large range of its vertical axis of rotation, and parts of the upper limbs of patients or medical personnel can be then pinched here.
U.S. Pat. No. 6,058,531A describes another version of the locking mechanism where the guard rotates around the horizontal axis and where in each position at least a part of the patient support is covered by the guard against the patient falling out of bed. The movement of this guard is limited by a cut in a disk to which the guard is permanently fixed. This disk is rotationally attached to the bed frame.
JP2005334511A shows another solution. The guard consists of several parts which are mutually rotational around the vertical axis, always by a maximum of 90°. Part of the side rail rests against the ground via a rest. Unlocking is performed in the following manner: after rotating the lever it is possible to lift the rest and rotate the relevant number of parts of the guard to the required position in relation to the bed side rail, which at least one part of the guard is fixed to.